Adjustable scaffold



C. DALY, JR

June 4, 1935.

ADJUSTABLE S CAFFOLD Filed Sept. 6, 1934 3 Sheets-Sheet l June 4, 1935. c. DALY, JR

ADJUSTABLE SCAFFOLD Filed Sept. 6, 1934 3 Sheets-Sheet 2 C. DALY, JR

June 4, 1935.

ADJUSTABLE SCAFFOLD 5 Sheets-Sheet 3 Filed Sept. 6, 1934 Patented June 4, 1935 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to adjustable scaffolds for usein the erection of buildings and other structures.

An object of the invention is to provide an improved adjustable scaffold including a base and a series of arms associated with each other in a manner to support a scaffold plank, in combination with improved means for raising and lowering and extending the length of said arms whereby the height of the scaffold may be varied, as desired.

Another object of the invention is to provide an adjustable scaffold having series of scaffold arms pivoted at their lower ends, in combination with novel mechanism supported by the scaffold base for raising and lowering said arms and simultaneously extending the length thereof to vary the height of the scaffold.

Various other objects and advantages of the invention will be apparent from the following description, reference being made to the annexed drawings, in which:-

Fig. 1 is a side elevation of a scaffold embodying the present invention.

Fig. 2 is an end elevation of the scaffold, the base and operating structure being in section on the line 2-2 of Fig, I,

Fig. 3 is a horizontal sectional view on the line 3-3 of Fig. 1.

Fig. 4 is an enlarged detail View showing the manner in which the upper longitudinally movable portions of the scaffold arms may be satisfactorily supported by the lower scaffold arms.

Fig. 5 is a cross sectional view on the line 55 of Fig. 4.

Fig. 6 is a cross sectional view on the line 66 of Fig. 4.

Fig. 7 is a side elevation showing an alternative form of the invention.

Fig. 8 is an end elevation of the scaffold shown in Fig. '7.

Fig. 9 is a horizontal sectional view on the line 9-9 of Fig. 7. r

Fig. 10 is a sectional view on the line l0|fl of Fig. '7.

Fig. 11 is a sectional view on the line I II I of Fig. 10.

The rigid base I has at one end a pair of rigid upwardly extended arms 2 to each of which the 0 lower end of an arm 3, in the form of a channel bar, is connected by a shaft 4. Preferably the channels of the bars 3 open inwardly toward each other.

A longitudinally movable arm 5, in the form of a channel bar, extends into the channel of each of the arms 3, being guided and supported by rollers 6 carried by the arm 3 and rollers 1 carried by the lower end of the arm 5. The rollers 6 operate against the flanges of the bar 5 and the rollers I operate against the flanges of the bar 3. A cross member 8 is attached to the lower ends of the arms 5, and a cross member 9 is attached to the upper ends of said arms. Thereby, the arms 5 are held in spaced relationship, said arms 5 and the connections 8 and 9 constituting a strong frame, which may be moved longitudinally with respect to the supporting arms 3.

Upwardly extended arms I0, similar to the arms 2, are rigidly supported adjacent to the opposite end of the frame I and the lower ends of a pair of arms I I, in the form of channel bars, are pivoted to the upper ends of said arms I0. Preferably the channels of the bars II open inwardly toward each other.

A longitudinally movable arm I2, in the form of a channel bar, extends into the channel of each of the arms I I, being guided and supported by rollers arranged and mounted like the rollers 6 and I that support the longitudinal arms 5. The longitudinally movable arms I2 are connected at their lower ends by a cross member like the cross member 8 and at their upper ends by a cross member I3 like the cross member 9. A bar I4 is supported by clips l5 attached to the cross members 9 and I3 and is designed and intended to cooperate with a similar scaffold to support the planks I6.

A pair of inwardly open channel bars I1 are rigidly attached to supporting arms I8 that are rigid with the frame I and constitute guides or rails for rollers I9 rotatively connected with the lower ends of levers 20. The lower ends of the levers 20 have angularly extended arms 2| pivotally connected with the outer ends of links 22, the inner ends of which are pivotally connected with a cross member 23. Fulcrum links 24 have their upper ends connected with the levers 20 by pivots 25 and have their lower ends pivoted to the inner arms I8.

A rod 26 is rotatively supported by the frame I and held from longitudinal movements by collars 21. The rod 26 is threaded and is screwed through a nut or other appropriate member 28 attached to the cross member 23. The outer end ate the levers 20 to raise or lower the upper ends thereof. Rotation of the rod 26 to move the member 23 in a direction away from the lower ends of the arms 3 will lower the upper ends of the levers 2B, and opposite rotation of said rod 25 will raise the upper ends of said levers 20.

An axle member connects and is supported by the upper ends of the levers 29. The arms 3 and H are crossed and extend upwardly at opposite sides of the axle member 33. Rollers 3| mounted on and rotatively supported by the axle member 30 constitute'sup'ports for the respective arms 3 and H, sothat said arms will be supported in crossed relationship, as shown in Fig. 1.

It should now be apparent that when the rod 26 is rotated in one direction the upper ends of the levers 28 and thereby the rollers 3| will be lowered, and that rotation of said rod 26 in the opposite direction will raise the upper ends of the arms 3 and II. As an incident to the lowering of the arms 3 and the arms 5 and I2 are likewise lowered, being moved downwardly longitudinally with respect to the arms 3 and II, respectively. And, when the arms 3 and H are raised, the arms 5 and |2 are moved upwardly longitudinally along the arms 3 and respectively. A wire or rope 32 has its lower end attached to a part 33 of the frame l. Said wire or rope extends upwardly over a roller 34 and downwardly and is attached to the connecting member 8 and supports and operates the longitudinally movable frame, of which the arms 5 are the side members. Outward movement of the lower ends of the levers 2B in a direction away from the rigid frame member 33, with which the lower end of the wire or rope 32 is connected, moves the roller 34 vertically in a downward direction and consequently lessens the distance between said roller and the frame member 33, thereby permitting the longitudinally movable frame with which the upper end of said wire or rope 32 is connected to move longitudinally with respect to the supporting arms 3. Upward movement of the upper ends of the levers 20 reverses this operation and moves the longitudinally movable frame upwardly and longitudinally with respect to the supporting arms 3.

A similar wire or rope 35 has its lower end attached to a'rigid part 35 of the part I and extends upwardly and over a roller 31 rotatively mounted on the axle member 3! and downwardly to connect with that analogue of the cross member 8 at the lower end of the frame including the arms i2, Consequently the frame, of which the arms P2 are apart, will be moved longitudinally in a downward direction when the upper ends of the oted to one end thereof the lower ends of a pair of arms 39, in the formof channel bars, opening inwardly and to the opposite end thereof the lower ends of arms 40, in the form of channel bars, also opening inwardly. Channel bar arms 4|, constituting side frame members, are mounted for longitudinal movements in connection with the arms 39 in the same way that the arms 5 are mounted for longitudinal movements in connection with shaft.

which support a bar on which the scaffold planks 46 are mounted.

A shaft 47 is rotatively supported by the frame 33 and has construction 48 on one end thereof for engagement with a wrench or lever to rotate said Pinions 49 are attached to the shaft 41 and mesh with pinions 50 attached to stub shafts 5| rotatively supported by the frame 38. One of the shafts 5| has universal pivot connection 52 with the lower end of a threaded shaft 53, the lower end of which is mounted in a bearing 54 on a frame member 55 supported by the lower ends of the arms 39 and the upper end of which is suped. The other shaft 5| has universal pivot connection 57 with the lower end of a threaded shaft 58 mounted in a bearing 59 supported by a frame member 80 attached to the lower ends of the arms 49, the upper end of said shaft 58 being journalled in a support 6| attached to the upper ends of said arms 40. The shaft 58 is screwed through a sliding member 58' supported for sliding movements ported in a frame member 56 attached to the upper ends of the arms 39. The shaft 53 is threadalong the arms 42 (Fig. 8) and the shaft 53 is I screwed through a similar sliding member 58' supported for sliding movements along the arms 4| (Fig. 11) The arms 39 are supported by rollers 62 rotatively supported by the arms 42 and the arms 40 are supported by rollers 63 rotatively supported by the arms 4 I.

A wire or rope 64 has one end attached to the frame member 55 and passes over a roller 65 on the sliding member 58' that is supported by the arms 4! and has its upper end attached to the frame member 43 connecting the lower ends of the arms 4| (Fig. 10). A similar wire or rope 65 has its lower end attached to the frame member 65 and passes over a roller 61 mounted on that sliding member 58 that is supported by the arms 42 and has its upper end attached to the frame member 43 that connects the arms 40.

When the shaft 41 is rotated, both shafts 53 and 58 are simultaneously rotated, thereby moving the members 58 upwardly or downwardly, depending upon the direction of rotation of said shaft 41. Since the wires or ropes 64 and 66 are arranged in the manner described, they will be relaxed to permit the arms 4| and 42 to move downwardly or tensioned and operated to move said arms upwardly,

It is now apparent that this invention obtains all of its intended objects and purposes efliciently and satisfactorily and may be varied within the scopeof equivalent limits without departure from the nature and principle thereof.

I claim: 1. An adjustable scaffold comprising a base frame, a pair of crossed frames having their lower ends pivoted to said base frame, an extension frame supported by each of said pair of frames, a shaft rotatively supported by said base frame, and mechanism operative by said shaft to raise and to lower said pair of frames when said shaft is rotated.

2. An adjustable scaffold comprising a "base frame, a pair of crossed frames having their lower ends pivoted to said base frame, an extension frame supported by each of said pair of frames, a shaft rotatively supported by said base frame, mechanism operative by said shaft to raise and to lower said pair of frames when said shaft is rotated, and mechanism for moving said extension frames longitudinally beyond said pair of frames when said pair of frames are raised as aforesaid.

3. An adjustable scaffold comprising a base, a pair of frames crossed above said base and having their lower ends pivoted to said base, an extension frame supported by each of said pair of frames, a shaft rotatively supported by said base, connections operated by said shaft for swinging said pair of frames upwardly when said shaft is rotated in one direction, and means for moving said extension frames longitudinally beyond said pair of frames when said pair of frames are swung upwardly.

4. An adjustable scaffold comprising a base, a pair of crossed frames having their lower ends pivoted to said base, an extension frame supported by each of said pair of frames, means for supporting said pair of frames in upwardly extended position and in crossed relationship, a shaft rotatively supported by said base, and mechanism operative by said shaft to swing said pair of frames upwardly when said shaft is rotated in one direction.

5. An adjustable scaffold comprising a base, a pair of crossed frames having their lower ends pivoted to said base, an extension frame supported by each of said pair of frames, means for supporting said pair of frames in upwardly extended position and in crossed relationship, a shaft rotatively supported by said base, mechanism operative by said shaft to swing said pair of frames upwardly when said shaft is rotated in one direction, and mechanism for moving said extension frames longitudinally along said pair of frames when said pair of frames are swung upwardly as aforesaid.

6. An adjustable scaifold comprising a base, a pair of frames having their lower ends pivoted to said base, a rotary shaft supported by said base, means for supporting said pair of frames in upwardly extended crossed relationship, and mechanism operated by said shaft for operating said means to swing said pair of frames upwardly when said shaft is rotated in one direction.

7. An adjustable scaffold comprising a base, a pair of frames having their lower ends pivoted to said base, a rotary shaft supported by said base, means for supporting said pair of frames in upwardly extended crossed relationship, mechanism operated by said shaft for operating said means to swing said pair of frames upwardly when said shaft is rotated in one direction, extension frames supported by said pair of frames for longitudinal movements, and means for moving said extension frames longitudinally to extended position beyond said pair of frames when said pair of frames are swung upwardly as aforesaid.

8. An adjustable scaffold comprising a base, a pair of frames having their lower ends pivoted to said base, means supported by said base for supporting said pair of frames in upwardly extended crossed relationship, a rotary shaft supported by said base, mechanism operative by said shaft for operating said means to swing said pair of frames upwardly when said shaft is rotated in one direction and to move said means downwardly when said shaft is rotated in the opposite direction, and means mounted on said frames for supporting scaffolding.

9. An adjustable scafiold comprising a base, a pair of frames having their lower ends pivoted to said base, means supported by said base for supporting said pair of frames in upwardly extended crossed relationship, a rotary shaft supported by said base, mechanism operative by said shaft for operating said means to swing said pair of frames upwardly when said shaft is rotated in one direction and to move said means downwardlywhen said shaft is rotated in the opposite direction, extension frames supported by said pair of frames for longitudinal movements, mechanism for moving said extension frames longitudinally with respect to said pair of frames when said pair of frames are swung upwardly as aforesaid, and means supported by said extension frames for supporting scaffolding.

10. An adjustable scaffold comprising a base, a pair of frames having their lower ends pivoted to said base, means for supporting said frames in upwardly extended crossed relationship, a rotary shaft supported by said base, extension frames supported by said pair of frames for longitudinal movements, and gearing operative by said shaft for moving said extension frames longitudinally beyond said pair of frames and for swinging said pair of frames upwardly when said shaft is rotated in one direction.

11. An adjustable scaffold comprising a base, a pair of frames having their lower ends pivoted to said base, means for supporting said frames in upwardly extended crossed relationship, a rotary shaft supported by said base, extension frames supported by said pair of frames for longitudinal movements, gearing operative by said shaft for moving said extension frames longitudinally beyond said pair of frames and for swinging said pair of frames upwardly when said shaft is rotated in one direction, and means in connection with said extension frames for supporting scaffolding.

CHARLES DALY, JR. 

